example
<slide id=x-1 caption="A slide">
<h4>A header</h4>
<ul>
<li> item 1 </li>
<li> item 2 </li>
</ul>
</slide>
A description of the origin of this approach can be found at
http://www.cs.vu.nl/~eliens/online/hush/manuals/man/man8/ht-ml.html
http://www.cs.vu.nl/~eliens/online/papers/htf4